Multifuel engines include any type of engine that is designed to burn multiple types of fuels at different times of operation. For example, dual fuel internal combustion engines use a liquid fuel, such as diesel fuel, and a gaseous fuel, such as natural gas, as fuels, and they nominally run under lean operating conditions. Hydrocarbons in the exhaust from dual fuel engines include short chain alkanes such as methane, ethane, or propane. The amount of hydrocarbons in the exhaust from dual fuel engines increases as the substitution rate of gaseous fuel for liquid fuel increases. In addition, certain fuels, such as diesel fuel and natural gas, contain sulfur that is released into the exhaust as SO2 and SO3, collectively referred to as SOx herein.
In order to meet emission regulations, hydrocarbons in the exhaust of a dual fuel engine must be lowered using an appropriate oxidation catalyst in the exhaust aftertreatment system of the engine. However, oxidation catalysts that are effective in oxidizing short chain alkanes may also be sensitive to sulfur levels in the exhaust, which could cause deterioration and/or deactivation of the oxidation catalyst over time as the oxidation catalyst is exposed to the SOx and other contaminants. Accordingly, there remains a need for further contributions in this area of technology.